1. The Field of the Invention
This invention relates generally to an apparatus and method for restoring storage media. More particularly, the present invention relates to an apparatus and method for removing scratches and similar imperfections from the surface of an optically read storage medium, such as a compact disc (CD), digital video disc (DVD) and the like.
2. The Relevant Technology
Optically read storage media, such as audio, video and computer compact discs (CDs) and the like, are increasingly used as the storage medium of choice for both computer software, audio, and video content. Such media provides an extremely high storage capacity in a relatively small space, and the digital format provides for a superior sound and video quality during playback. CDs and related optically read media are usually constructed by laminating a clear protective layer over a metal disc or base which contains digitally encoded information. The clear protective layer prevents the metal disc or base from being damaged during normal use. Digital information is encoded on the metal disc or base via the formation of "pits" and "lands" that are arranged in a concentric circular track. These pits and lands are used to represent digital information, and thus can be used to store a digitized version of sound, or similar digitized form of information, on the disc.
In operation, the digital information is essentially reproduced from the compact disc by scanning its surface with a laser beam. The scanning laser is focused just below the protective surface of the disc, so that minor imperfections in the protective layer do not effect the transfer of information from the disc. As the beam passes over the surface of the disc, it is reflected by the surface of the metal disc or base. In addition, as the beam is reflected it is also modulated by the pits and lands contained on the metal disc. The modulated laser light is detected by receivers and the digital information represented by the modulation is decoded and converted into a form usable by the particular apparatus containing the disc, such as a computer or compact disc player. As is well known, the digital storage and retrieval of information provides high data quality and reproduction.
While the plastic coating present on most optically read media provides a certain degree of protection, scratches and related imperfections in the coating medium can occur over time and/or from misuse of the medium. These scratches or related imperfections can cause a loss or interruption of data in computer software media, or negatively offset the sound and/or video quality in an audio/video medium. If the coating has a significant number of imperfections, the medium may be completely unusable.
It would therefore be an advance to provide the ability to restore damaged optical storage media. In particular, it would be advantageous to provide the ability to remove scratches and other imperfections that exist in older, or mishandled discs and thereby prolong the life of the disc.